Figure 4.

Concentration-dependent uptake of choline and albitiazolium by P. falciparum IRBC and isolated parasites. The entry of choline (A) or albitiazolium (B) in purified mature-stage IRBC was measured after 10 min (choline) or 8 min (albitiazolium) incubation in the presence or absence of 150 µM furosemide. When furosemide was used, IRBC were pre-incubated for 8 min in the presence of furosemide before the addition of choline or albitiazolium. Uptake into normal RBC was measured only in the absence of furosemide. The entry of choline (C) and albitiazolium (D) into saponin-free parasites was measured after 10 min (choline) or 8 min (albitiazolium) incubation at 37°C. The results are expressed as means ± SEM (n≥ 3).